


Skin Trade

by 0hHeyThereBigBadWolf



Category: Merlin (TV)
Genre: But It's S5 Merlin So What Else Is New, Do Not Re-Post To Another Site, Happy Ending, M/M, Magical Bond, Merlin is slightly dark, Mildly Dubious Consent, Smut, Tags Are Hard, When In Doubt Turn To Sex Magic, non-consensual bonding, not as bad as it sounds
Language: English
Status: Completed
Published: 2020-02-26
Updated: 2020-02-26
Packaged: 2021-02-28 00:15:34
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 3,636
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/22914601
Author URL: https://archiveofourown.org/users/0hHeyThereBigBadWolf/pseuds/0hHeyThereBigBadWolf
Summary: In the end, the answer is simple. Simple enough that Merlin isn't certain if he wants to laugh or cry or scream or perhaps some mix of the three. If he wants to ensure that Mordred will never bring harm to Arthur, he simply needs to take away the Druid's choice of doing so.
Relationships: Merlin/Mordred (Merlin)
Comments: 14
Kudos: 302





	Skin Trade

**Author's Note:**

> Pretend for the sake of this fic that Merlin burned bridges with the Kilgharrah the Painfully Cryptid much earlier, Arthur and Gwen's relationship wasn't slapped on like a bad heterosexual wallpaper job, and Mordred, going by the likely fanon assumption he's about 18-19 in S5, falls squarely in the "horny dumbass" category of things.

In the end, the answer is simple.

Simple enough that Merlin isn't certain if he wants to laugh or cry or scream.

He finds the book in the library's hidden room, the same place he had found the goblin. It'd been put out of his mind for over a fortnight after _that_ entire debacle, but he'd remembered and returned to it once Geoffrey fell asleep after his afternoon tea. Oh, _oh,_ the books he has found there, hidden away on the shelves; they make Gaius's book of spells look like a packet of children's doggerel. He's careful in reading them, exchanging them out one or two at a time, in staggered visits to keep from arousing Geoffrey's suspicion.

After Ismere and their encounter with Morgana _,_ he's been spending more and more of his time with these books, hoping to find something that might help—though how he can help Arthur when the king is destined to be his own bane is beyond him. He has no truck with Kilgharrah's prophecies, such as they are. The dragon has sat in the darkness too long; it has eaten its way into his heart, poisoned him, and whatever is left bears no good will for anyone. Perhaps if he hadn't put so much faith in the dragon's words, Morgana wouldn't be what she is. The chains of blood-guilt sit heavy around him, knowing his own hand in the forging of the High Priestess. Now, with Mordred here in Camelot, he will not fall down that same path again. Still, he cannot ignore that the Druid is foretold to kill Arthur, the vision he had seen of the two slaying each other; something must be done about that.

Sitting huddled in his bed, reading by a golden tongue of sorcerer's fire, Merlin has finally found his answer, tracing his fingers over the pages.

A thrall.

In order to increase their power and maintain control of stronger magics, sorcerers used to form triumvirates of power—a sorcerer, a familiar, and a thrall. The familiar is the sorcerer's animal to call, a natural beast or a skinchanger, and the thrall is the sorcerer's human servant. Except they needn't be strictly human. They could be a lesser sorcerer. The bond between sorcerer and thrall is one of the greater magics; woven tight enough by a sorcerer powerful enough, it can be powerful to compel obedience. He is Emrys. Supposedly there is no magic greater than his. Surely, if he makes Mordred into his thrall, he can order the Druid to never bring harm to Arthur.

Now the question is _how_ to make Mordred into his thrall. He doubts the young man will allow himself to be bound, especially if he still serves Morgana. And even if he doesn't, their relationship isn't exactly the greenest of pastures; he'll be suspicious of Merlin asking such a thing of him after making it clear there is no trust between them.

Merlin turns the page and pauses, staring. The next page is given over to an illustration, a line drawing—a quite _explicit_ line drawing; reading the opposite page, he understands why. A thrall isn't simply a servant, they're meant to be a companion, a friend, a lover. Whilst it could be a more platonic relationship, the bond is strongest when made in blood and seed.

And there is his answer.

Mordred might not give himself over as Merlin's thrall…but he might give himself over as a lover. It does not say anywhere that the bond need be taken on _knowingly._ The blood might be harder to get, but…a good tumble in bed, one might bite a little too hard, scratch a little too deep. He's heard stories from Gwaine, jesting about his 'battle wounds.' He could do that.

A part of him recoils from the idea of knowingly taking an enemy to bed, in essence making a whore of himself. However, that part has been chipped and gouged at for years now, and whatever is left, he is used to smothering beneath logic. It need only be the once, just to form the bond. Once made, Mordred shan't be able to break it, and Merlin can know for a certainty that the young man can do no harm. Short of outright murdering the young man, this is the best way to keep Arthur safe from Mordred. He wonders if killing Mordred might be the better route, if he's simply being a coward and trying to assuage his own guilt from the folly of Morgana. Still. Nobody deserves to die for something they haven't done yet, might not do at all. Either way, he'll be chipping away another part of his soul. It's simply a choice of which one it will be.

He draws his fingertip down the page, reading over the incantation again and again, until the words are etched bright in his memory.

Surprisingly, getting Mordred back to his chambers is the easiest part.

Gaius isn't there, he's out of the city, sent to look after a suspected outbreak of flux in another town, which means Merlin has the physician's chambers to himself. Arthur might not always be the most gracious of masters, but he gives Merlin light duty until Gaius's return, allowing him to handle the physician's normal deliveries on his own. So he waits until after training, when he's in the armoury with the knights ensuring none of them have suffered actual injuries under the guise of masculine stoicism. Mordred is near always the last one left in the armoury, subtly delegated the task of clearing up after the others—a rite of passage for all young knights. Once he knows they're alone, as he is packing up his unguents and compresses and Mordred is replacing the training swords and light shields, he tells the Druid to meet him in the physician's chamber after the night bell. It isn't a request, and even if Mordred has taken an oath to Arthur and Camelot, he is still a sorcerer first. He won't disobey Emrys.

When Mordred walks into the physician's chamber, Merlin is waiting for him. "Close the door," he instructs. Once the door is shut, he casts a ward over the door, ensuring that their words will remain in here, and that no one can enter without his permission. "Habit," he says when Mordred raises his brows. "I want to talk to you about something. Quietly."

"Oh. I see." Mordred casts a glance towards the other empty chair, waiting for Merlin's nod before he sits down. Any other situation, it'd be almost laughable, a knight waiting for the grace of a servant to take his seat. "What is it you wished to speak of, my lord?"

Merlin doesn't correct him on the address. If anything, it will only help, reminding him of the difference between them. "Have you ever taken a lover, Mordred?" He's sick unto death of playing word games.

The young man stares at him a moment, a flush spreading up the sides of his neck. "I—yes, but…not for a long time."

That brings a genuine smile to his face. Young men. He has no idea what a long time truly is. "Another Druid? A sorcerer?"

"Yes, my lord."

"Anyone in Camelot?"

The flush deepens, creeping a little higher into his cheeks. "No, of course not. I couldn't…you know why."

He does know. Magic is a gift, but betimes it could be its own shackle. Merlin has to constantly concentrate on keeping his magic from accidentally sliding out of him on a daily basis. Though there is no sensation that could truly match it, he would draw it akin to keeping the muscles of one's stomach tensed all the time, having to always think about it lest he accidentally relaxes. And as great as his control is, he couldn't ever hope to keep it hidden in the midst of intimacy.

No one can ever say that Mordred isn't a sharp lad. In the stretch of silence that follows, his eyes widen slightly, lips parting soundlessly as he stares at Merlin. When Merlin only gazes back at him in silence, brows raised, the young man closes his mouth again and swallows hard a few times. "You've not…?"

"Of course not," Merlin echoes back at him with wry amusement.

There's another length of quiet. He wonders if Mordred is counting back the years to when Merlin first came to Camelot and perhaps reevaluating his definition of a 'long time.' He swallows hard again; Merlin can hear the click of it in his throat. "Is…is that why you asked me here?" he finally asks in a smaller voice.

Sharp lad. "You can say no."

Mordred shifts his weight on the chair, making it creak. "I didn't think you were all that fond of me."

He takes in a deep breath, lets it out slow. "That's a conversation and a half on its own," he replies at last. "But I _am_ fond of you. It's simply…complicated."

"Can you uncomplicate it?" It isn't a demand. A genuine question, a faint ache beneath the words, a simple wanting to _know._

"Perhaps one day." He turns his head to gaze at the Druid once more. "It's your choice." Patience is a virtue. He might not wait forever, but he can wait long enough to let Mordred come to him, at least a little. If he spooks the lad, Mordred might bolt, and even if binding him in thrall is the best solution, Merlin won't force himself on anyone.

Silence reigns in the physician's chamber, broken only by the snap of the fire in the hearth, red-gold tongues licking at the resinous hearts of the logs. The other chair creaks again; Merlin doesn't look away from the fire, making shapes in the bright leap of the flames. Fingertips brush his wrist, and he looks up at the touch to see Mordred standing over him, bright-eyed and flushed up. "I'm not a bedwarmer," he says softly.

"I know. I'd never ask that. I don't know what we are yet, but it is more than that." _You have no idea how much more._

Mordred bites his lower lip, and Merlin is almost ashamed of how much he enjoys the motion. "May I tell you something?" he asks, then goes on without waiting for an answer. "I've dreamt that you would ask me such a thing since Ismere. Even when you near frozen in the snow, I wanted…." He swallows hard. "I liked your anger. It made your magic feel…brighter. Sharper."

Merlin pushes to his feet now, standing so close that he can feel the heat of Mordred's body through his clothes, see the flecks of gold in his eyes. "Do you still like me now that I am not so angry?" He's going to hell for this.

"Oh, yes," Mordred breathes out.

He begins to lean in for a kiss, but Merlin snatches a fistful of his hair, gripping the silken curls tight in his fingers and holding him still. "My way."

This close, he can see the pulse in the hollow Mordred's throat leap. "Yes, Emrys," he whispers.

Ah, he is definitely going to hell. "Good. Now…choose a door." He casts a pointed glance towards the door of the chamber, then tilts his head in the direction of the bedchamber behind him. The relative privacy it offers is unneeded given they're already alone, but he knows from experience that the patient cot is uncomfortable and he is _not_ going to do this on Gaius's bed.

Mordred's breath quickens against his skin, and he nods towards the bedchamber.

Loosening his grip on the young man's hair, Merlin makes a sweeping gesture with one arm, and Mordred almost bolts up the few steps to the small room. He follows at a more sedate pace, wondering if damnation will truly be as terrible as everyone says.

The young man doesn't try to grab him again, waiting with barely restrained energy for Merlin's direction, for _instruction._ Stepping in closer, he reaches up and slides his hands over Mordred's shoulders, feeling the responsive shiver and appreciating the firm swell of muscle beneath the fabric of his tunic. If nothing else, the Druid is well-made. One could have worse bedmates. "You said once that you would never forgive me," he murmurs, taking slow steps forward, walking the young man backwards. Why in seven hells he'd mention that now, he cannot say, except that perhaps he's doing it again, trying to quiet that cold kernel of guilt by offering ground to refuse. He has a habit of doing that; perhaps he should work on breaking it.

Mordred swallows hard as he backs up. "Yes."

"Have you?"

"Forgiven?" The backs of his knees meet the bed, and he drops down ungracefully, now having to tilt his head all the way back to look at Merlin. "Not so much. But understand?" He nods slowly; his hands slide over Merlin's waist, up his flanks. "Yes. That I've done. I understand…it must be hard for you. Living here. Doing what you do. Choices must be made, and there is rarely ever a right answer."

Merlin presses his lips together on a smile despite the painful ache of those words, and he slides his hands back through Mordred's hair. "No, there's not." If only he knew how true those words are, the choices that have already been made. He plucks at the young man's tunic. "Off."

Mordred crosses his arms and yanks the garment up over his head, casting it aside. Underneath, he's pale but not unmarked, etched with scars here and there. Merlin frowns when he sees one mark, or rather, the lack of one. "Where is it?" he asks, brushing his fingertips over Mordred's chest.

"A glamour, just in case." Magic shivers in the air, and the triskele tattoo reappeared on his skin, fading in like a bruise.

He traces over the spirals with a fingernail, feeling Mordred shiver eagerly under his touch. The dark hair on his chest is surprisingly soft and fine. "Back," he says.

Mordred slides further up onto the bed, lying on his back; he starts on the laces of his trousers, but Merlin waves a hand, stilling the young man with just a brush of magic. Not enough to alarm him, just to send the message. "Hands on the headboard, keep them there."

Breath coming quicker now, the young man raises his arms above his head, curling his hands over the rough-hewn wood. And he keeps them there.

Merlin gazes at him for a long moment, then reaches out—not physically, but with his magic, feeling out Mordred's own magic, testing, tasting. Mordred's power runs hot; he has an affinity for elemental magic, fire. But he's not as insubstantial as flame. He's heavier than that, _solid,_ as though Merlin could sink both hands into his power, work it around his fingers like taffy, and it would stick to him when he pulls away, dragging at his skin. It responds eagerly to his power, pressing back up against him, not trying to push him away, but with eagerness, rolling against him like a cat demanding affection. Good. It'll be easier to form the tether with less resistance. The thought comes to him belatedly, the rest of him unexpectedly absorbed in the experience, so wholly new yet natural and _right._ He's never done this to anyone. He's never been able to. His belly tightens, twisting up with neither hunger nor fear.

"Emrys," Mordred gasps out, eyes tight shut as he writhes against the bed, still clutching the headboard. "Emrys, I-I— _please."_

Merlin catches his breath sharply, and he steps closer to the bed, pulling off his tunic and starting on his trousers. Mordred watches him with dark eyes, chest heaving, and when Merlin steps out of his smallclothes, he makes a strangled whine in his throat. "Don't move," he repeats when he sees the Druid's hands start to loosen on the headboard, and the young man tightens his grip immediately. Goddess have mercy, he's starting to understand why people get such satisfaction out of giving orders.

He opens the cupboard beside his bed, going in search of the oil; as he does, he reaches out for Mordred with his magic once again, this time unlacing the young man's trousers with it with practiced ease. It's one of the small magics he's always allowed himself, dressing and undressing. Turning back towards the bed, he catches his breath again, sharp in his throat.

Mordred is spread out on the small bed with eager readiness, stripped mother-naked. His back is arched as if chasing the feeling of Merlin's magic against his skin, head back against the pillows, arms trembling from the white-knuckle grip he has on the headboard.

Gripping the vial tight in hand, Merlin wastes no time in climbing up onto the bed, kneeling between Mordred's legs, which immediately wrap around him as best they can. He is more used to doing this to himself, but he imagines the principle to be the same, simply applying the same knowledge from a different angle. Mordred makes eager little noises in his throat, almost yelping as he pushes back into Merlin's fingers, hips arching.

"May I?" he asks softly, using his free hand to slick himself as he continues to work Mordred open with his fingers. There goes that habit of his again. He needs to fix that.

_"Please,"_ Mordred implores.

Withdrawing his fingers, he spreads Mordred's thighs further apart with both hands and plunges in without any further hesitation, pushing in up to the hilt. If he goes too fast, if it hurts, Mordred certainly doesn't show any sign of it, a loud cry torn out of his throat.

For a moment, he holds himself still against the young man, trembling, gasping. It's almost too much, slick and hot and tight, still so very tight around him, and Mordred is so very eager, squirming and arching, legs clutched tightly around Merlin's waist. Once he's certain that he can breathe again and can bear to move, he eases out and thrusts back in, a sharp snap of his hips; now Mordred _does_ yelp, a high, eager little sound in the back of his throat. The sound makes his belly tighten again, and he starts moving, finding a rhythm in it, chasing those wonderful little noises. He curls his hands around Mordred's hips and digs his fingernails in hard there, hard enough to draw blood. He needs only a little.

Beneath him, Mordred gives a long, low moan in his throat. "Oh, _oh,_ please, Emrys, _Merlin,_ let me—let me—"

"Touch me," he rasps out.

Immediately, the young man releases the headboard and wraps both arms around Merlin's back, hands clutching at his shoulder blades, nails raking fire over his skin.

Heat spills down the length of his spine and gathers low in his body, a white-hot spring coiling up tighter and tighter. Merlin can feel his magic drawing up in response to it, twining deeper with Mordred's, casting off bright sparks of red-gold energy in the air. The spell of binding comes to him easily, despite everything; this is when it is meant to be cast, after all, sliding up through the haze of pleasure to blaze bright in the forefront of his mind. He drags his nails over Mordred's hips hard, feeling the skin give, the well of blood against his fingertips.

Vocal as he is, Mordred climaxes with only a strangled gasp, his eyes spilling into gold as he spills heat onto their skin, just as Merlin finds release inside him.

Blood and seed.

Merlin whispers the incantation and plunges his magic into Mordred.

For a glorious moment, it's almost as if they've slipped their skins, become closer than any two people could be, briefly blurring the boundaries of who they are as individuals, merging into one another like streams into a river. He anchors the tether in the very core of Mordred's self, twisting it through every inch of his magic, burying it into him so deep it won't ever come out again without breaking everything else irreparably. He sees Mordred's golden eyes widen in realisation, feels his belated pushback, but it's too late. Mordred is _his,_ so very much his. If Merlin told him to take up his sword and fall upon its blade right now, he would do so. But he won't. He won't need to. Mordred will never be able to so much as _look_ at Arthur wrong now. He is _Merlin's._

When they come back to themselves, gasping and trembling, Merlin is still braced above the Druid, sticky warmth on their bellies. His back is afire from the scratches laid on him, and he can feel the warm trickle of blood from the deeper ones, threading down his spine.

"Bastard," Mordred whispers hoarsely.

"You have no idea," Merlin replies.

Curious, he feels out the new, shining tether binding them, woven of shining gold magic yet firm and fast as steel cable. When he plucks at it, Mordred gives a soft sound in his throat, squirming beneath him, an echo of pleasure reverberating back up the tether like vibration through a taut rope. Merlin feels deeper, following the tether, and Mordred doesn't try to keep him out, shields unravelling for him. Beneath his irritation at being unwittingly bound, a part of him is curled up and all but purring in delight, nearly a decade of aching soothed by knowing he finally _belonged,_ no longer an outsider, no longer set apart. Mordred's voice is dryly amused in his mind, reverberating up the tether, clearer and truer than any other Druid's mindspeak.

_[You know, you could have simply asked.]_

Smiling, Merlin lowers his head for a kiss.


End file.
